83-15-07 R1: Main Rotor Blade Inspection

83-15-07 R1 ROBINSON HELICOPTER COMPANY: Amendment 39-4762. Applies to Model R-22 series helicopters, certificated in all categories. Compliance is required as indicated (unless already accomplished). To detect cracks and to prevent possible fatigue failure of main rotor blades, accomplish the following prior to further flight after the effective date of this AD: (a) Conduct an inspection of the main rotor blades to determine the serial number of the installed main rotor blades. (b) Remove from service all Robinson main rotor blades P/N A016-1 Revision "W." Revision "W" main rotor blades have S/Ns 0600 through 0810. NOTE: Section 9.100 of the R-22 Maintenance Manual contains pertinent assembly/disassembly instructions, and Robinson Helicopter Company Bulletin No. 33 dated July 25, 1983, contains the same instructions as this airworthiness directive as well as shipping/warranty information. Main rotor blades removed by (b) should be either cut up in accordance with Robinson Helicopter Company Service Bulletin No. 33 or marked "UNAIRWORTHY" on both surfaces at approximately mid-span with lettering at least 2 inches high and "UNAIRWORTHY" impressed on the data plate using a metal stamp. (c) Equivalent means of compliance with the AD may be used when approved by the Manager, Western Aircraft Certification Field Office, FAA, P.O. Box 92007, Worldway Postal Center, Hawthorne, California 90009-2007. This amendment becomes effective November 21, 1983, as to all persons except those persons to whom it was made immediately effective by priority letter AD 83-15-07, issued July 28, 1983, which contained this amendment.